Chris, good on you for taking the trouble to clean up and I'm sorry you've
had such ridiculous replies from what normally tries to be a helpful and
sensible newsgroup. The person who lectured you on steam/smoke is an
ar**hole. Smoke detector technology basically detects anything that isn't
the usual mix of gases we call Air, so burning the toast, taking the lid off
a saucepan, opening a gas oven door, having a steamy shower or even a good
old fart can all set off a "smoke" detector.
My best advice is you should tell the person in charge of the fire alarm
(the facilities manager?) what you are planning to do and that you're
worried you might set off the alarm. He should be thankful you have the
common sense to ask first. That would be much better than him finding
you've been mucking about with the system yourself, or for the Fire Brigade
to turn up to find you in your Mrs Mop outfit.
Usually individual heads (if it's a modern digital system) or a particular
zone can be temporarily disabled at the alarm panel. The heads can be
unplugged (usually like a bayonet-type light bulb) to clean or replace them,
but DON'T try doing this with the system still active as it will set off the
alarm. The FM won't be too happy while part of the premises is unprotected,
so this needs to be for a very short period and he may want to get someone
to supervise you.
If you want to risk it, you can certainly cover the detector heads with a
plastic bag to exclude the water vapour, or even better, use a plastic glove
(I thought that was a great idea) but remember the alarm is still active and
covering up the heads doesn't guarantee you won't set it off. Then you'll
be in hot water as well as steam!
Peter